The demolition industry has a certain character for being a tough atmosphere in which brute force takes priority over calculated thought; however this impression is far from correct. There is a substantial amount of work that goes on behind the scenes of the demolition and construction sector that is firmly rooted in the academic arena.
One part of this unnoticed work is site surveying, or more precisely pre-demolition and post-demolition topographical surveying. This type of work calls for a great balance of specific technical knowledge as well as experience of the industry and a natural intuition for the intricacies of the job. This article explores the ins and outs of this work.
Topographical Surveys
A topographical survey is a study of the physical features of a particular piece of land. The aim of a topographical survey is to chart the naturally occurring and man-made traits of a specific landscape to a high degree of precision.
Topographical surveys could be carried out on a very wide range of environments, from open countryside to urban areas and across a variety of reliefs and land surfaces. Surveys can be developed to take into account a great number of factors, such as ground conditions or vegetation, and as such can be used for a number of tasks. A few of the more common uses are discussed below.
Common Applications for Topographical Surveys
Perhaps the most extensively used, and most generally recognised application for topographical surveys is cartography, or map making. Modern maps include a great amount of detail about the landscape they relate to, including waterways, elevations and ground surface, all of which will have been collected via a topographical survey.
Topographical surveys also have a key role to play in the construction industry. When people or organisations are looking to build any kind of structure they will need to carry out extensive surveys as part of the design phase of the project.
Surveys also play a key safety role in primary industries such as mining, or in other industrial sectors that interact with the land, such as demolition and infrastructure. Businesses in these industries will use surveys to plan their projects, but also to ensure that they can ensure the safety of their workforce on site. As a result, topographical surveys are often a legal prerequisite for these types of projects.
To conform with particular health and safety legislation a demolition survey is demanded before demolition work happening.
Types of Survey
The arena of topography addresses a large number of physical features so it is beneficial to determine what form of topographical survey is suitable for a particular scenario. A few of the more common types of survey necessary for construction sites are discussed below.
“Lie of the land” Surveys
These types of topographical surveys are designed to create a summary of the physical characteristics of any given plot of land. Although the information gathered by the survey will be extremely accurate, and might be very extensive, the objective of these surveys is to give a site summary.
These surveys will generally incorporate a boundary survey that sets out to determine the extent of the site and spotlight any specific restraints that are determined by the geography of the site. They can also include a level survey that will plot the elevation of the land and the various gradients that exist.
Building Surveys
Building surveys are more typically concerned with man-made constructions on a site, including the surveying of special equipment and even infrastructure characteristics. This type of survey is more regularly associated with the demolition sector because it can give a detailed plan of the structure to be demolished.
A building survey will probably include a measured survey, which involves creating a precise plan of the external and interior dimensions of a building. Depending on the requirements of the job, a measured survey could provide simple building “footprint” dimensions, or might produce a highly detailed plan of the structure. This information can be used to produce internal floor plans and even roof plans.
Content of a Topographical Site Survey
A survey of a demolition site will almost definitely include the details gathered by the types of boundary and building surveys described above. This information will be needed so the demolition firm can plan a demolition that is both adequate and safe. More often than not these surveys will also be legally requested.
Surveys will often include information about the utility services that are present on a site prior to any demolition or construction work happens. This is an essential safety aspect because any unmonitored destruction to pipes and cables carrying water, gas and electricity might be very dangerous. The information could also be used to plan new structures, based upon the existing supply of these ammenities.
Another aspect of the site study will often be an inventory of resources on the site. This type of study will be a quantity survey of the various types of materials that can be located on site, for example, tiles and masonry, concrete that can be utilised as hardcore or even timber. By getting an accurate audit of site materials the construction company can more precisely gauge the need to import building materials, or they can re-use the materials on a different project.
It is an apparent truth that before construction demolition must be done within sites that contain existing houses and other structures.
Importance of Site Surveys
Possibly the most important reason to perform a topographical site survey is to ensure the safety of the individuals who will be doing work on the site. The industries that most frequently call for site surveys are risky enough as it is without having to worry about the integrity of the ground on which they are working. Taking a detailed topographical survey can help to eliminate safety risks of this nature.
Another critical reason to get a suitable survey done is to highlight any potential difficulties that may arise because of the physical properties of the area. Certain things will not be evident on the surface of the site and will only be uncovered once digging or demolition has started. By then it may be too late to resolve these problems, or at best they will be expensive issues to solve.
The inventory of site supplies, as previously stated, can be of great benefit to a demolition or construction enterprise working on a project. Not only are construction materials themselves expensive, but transporting them to the site may be a very expensive task in itself. Any time that material can be reused on site provides an opportunity to save development time and funds.
Topographical surveys can also highlight other areas that will be of use to the project managers. For example, if the gradients on a site would be prohibitive to specific vehicles or machinery then a new entry route or alternative equipment will need to be found. Equally, a suitable site will need to be found for the base of management operations for the project. Good site surveying can help out in these less tangible ways.
Positioning of Survey Control
During the surveying and construction phases of a construction project, the apparatus required for the physical surveying of the site and control of the survey information will often be stored on-site. This is obviously a problem when it comes to the demolition period of a project since the equipment is both costly and sensitive. It is therefore wise to move this equipment off-site during demolition.
Once the demolition has occurred and the site has been deemed safe for workers to return to it, the surveying equipment can be restored to its initial position on site. This will allow for effective data gathering to take place for a post-demolition study, and retains a single point of contact for anyone who requires the topographical survey information. Most surveying companies will oversee this redeployment.
The demand for strict measurement and planning is critical in garage demolition projects given that homes or other buildings may be nearby.
Who can Perform Site Surveys?
Because topographical site surveys can play such a vital role in the success or failure of a building or demolition project it is critical that they are carried out thoroughly by the correct people. There are different divisions of site surveying and each one will have unique qualifications associated with it. Finding surveyors with these specific qualifications will certainly be advantageous.
When choosing a company to undertake the surveying work necessary for your project it will be wise to choose a company with a good reputation and a proven track record. Ask to see examples of their previous work and try to get feedback about their performance on past projects.
Who will use the Survey Information?
When an adequate level of information has been accumulated by a site survey it needs to be handed out to the appropriate people on-site. Who gets which pieces of information will largely depend on the job roles being performed, but can also rely on the stage that a project is at.
Project Planners
Project planners will usually require access to all of the information gathered by a topographical survey, though they will particularly need to use information regarding the physical relief of a site before the design phase, and a site materials inventory before they can prepare the construction phase.
Demolition Experts
Demolition organisations will want to know about the internal and exterior properties of any building or structures that they are arranged to take down. Whilst every project will have different requirements, demolition experts will generally need to know about the fundamental framework of a building and the materials it is made out of.
Site Engineers
Construction engineers on-site will be particularly interested in the survey information about the relief and topography of the site. It is normally the case that they will want to assemble on a flat surface, so they will use details about the natural lay of the land to calculate what work will be needed to create a stable foundation for any structure. They will want this information before and in the course of the construction stage of a project.